Our transcription: Planets have a variety of compositions, chemical make ups, and we think that came about because when the Solar System formed there was a range of temperatures from very high temperatures close in to the sun to much lower temperatures further out. The main difference in the Solar System is between the planets which are earth like by which we mean Mercury, Venus, Earth, and Mars, and the more distant planets, Jupiter, Saturn, Uranus, Neptune, and Pluto. These more distant planets are rich in ice and gas. The ice, in particular, is material that would not be able to condense close in to the sun in the region where the Earth formed, so to first approximation the dominant difference within our Solar System lies between the earth like planets and the more distant planets, and this, in turn, is related to the gradual decline in temperature as you go outward from the sun.